問題描述

我嘗試了多次，但無法成功獲得正確的語法——根據 PHP 5.5.12——從我的數據庫中獲取單行或多行.

I tried several times but cannot succeed in getting the right syntax—according to PHP 5.5.12 —to fetch single or multiple rows from my database.

session_start();
$con=mysqli_connect("localhost","root","","doortolearn");
if (!$con) {
    echo "Could not connect to DBMS";       
}
    $query="select * from teacher where tremail='$_POST[email]' and trpasssword='$_POST[password]'";
    $result=mysqli_query($con,$query);
    $flag=FALSE;
    while ($row=mysqli_fetch_array($result,MYSQLI_BOTH)) {
        $_SESSION['email']=$row['email'];
        $flag=TRUE;
    }

推薦答案

首先，$_POST[password]周圍沒有單引號':

First, you have no single quotes ' around $_POST[password]:

$query = "SELECT * FROM teacher WHERE tremail='". $_POST['email'] ."' and trpasssword='" . $_POST['password'] . "'";
$result = mysqli_query($con, $query) or die(mysqli_error($con));
$flag = FALSE;
while ($row = mysqli_fetch_array($result, MYSQLI_BOTH)) {
    $_SESSION['email'] = $row['email'];
    $flag = TRUE;
}

但除此之外，您是否甚至在此處設置了 MySQL 數據庫連接?我看到 $con 但這真的有效嗎?

But past that, do you even have a MySQL database connection set here? I see $con but is that really working?

此外，通過將 或 die(mysql_error($con)) 添加到您的 mysqli_query($con, $query) 行來檢查是否存在錯誤.

Also, check if there are errors by adding or die(mysql_error($con)) to your mysqli_query($con, $query) line.

此外，您有一個 $_SESSION 值，但您是否在腳本的開頭設置了 session_start?

Also, you have a $_SESSION value, but do you even set session_start at the beginning of your script?

但我也建議您使用 mysqli_stmt_bind_param 作為您的值，如果您不打算進行基本驗證，至少可以將它們轉義:

But I also recommend you use mysqli_stmt_bind_param for your values to at least escape them if you are not going to do basic validation:

$query = "SELECT * FROM teacher WHERE tremail=? and trpasssword=?";
mysqli_stmt_bind_param($query, 'ss', $_POST['email'], $_POST['password']);
$result = mysqli_query($con, $query) or die(mysqli_error($con));
$flag = FALSE;
while ($row = mysqli_fetch_array($result, MYSQLI_BOTH)) {
    $_SESSION['email'] = $row['email'];
    $flag = TRUE;
}

這篇關于如何使用 MySQLi 在 PHP 中獲取數據?的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！